WO2006129348A1

WO2006129348A1 - Semiconductor manufacturing apparatus

Info

Publication number: WO2006129348A1
Application number: PCT/JP2005/009944
Authority: WO
Inventors: Keizo Yamada; Minoru Matsuzawa
Original assignee: Topcon Corporation
Priority date: 2005-05-31
Filing date: 2005-05-31
Publication date: 2006-12-07

Abstract

A semiconductor manufacturing apparatus which can excellently detect vibration state of the semiconductor manufacturing apparatus itself or an object to be manufactured or an object to be inspected by the semiconductor manufacturing apparatus without disturbing original manufacturing operation or inspecting operation of the semiconductor manufacturing apparatus. The semiconductor manufacturing apparatus for processing or measuring a semiconductor substrate, which is either a semiconductor wafer itself or a substrate provided by processing the semiconductor wafer, is characterized in that the apparatus is provided with a capacitance measuring means for measuring a capacitance generated between the semiconductor substrate and a peripheral object arranged in the vicinity or periphery of the semiconductor substrate.

Description

Specification

Semiconductor manufacturing equipment

Technical field

The present invention relates to a semiconductor manufacturing apparatus used for manufacturing, inspecting, measuring, or evaluating a semiconductor device. The present invention also relates to a semiconductor manufacturing apparatus using an electron beam, an ion beam, light or electromagnetic waves. The present invention also relates to a semiconductor device evaluation apparatus (inspection apparatus) that performs process evaluation during the semiconductor device manufacturing process using an electron beam, ion beam, light, or electromagnetic wave.

Background art

[0002] A semiconductor device is one in which various functions are performed on a semiconductor wafer such as silicon (hereinafter simply referred to as a "wafer") to realize an electrical function. Semiconductor devices are getting smaller year by year due to the evolution of semiconductor processes. In the current semiconductor manufacturing equipment and semiconductor device evaluation equipment, semiconductor devices consisting of very small structures with a size of 0.1 microns or less are made and measured.

On the other hand, a wafer is a disk-shaped structure having a diameter of 20 to 30 cm. Such a disk-like structure has the property of easily vibrating when exposed to external force vibration. Wafer vibrations in semiconductor manufacturing equipment can cause process failures and measurement instabilities. Therefore, in the development of a semiconductor manufacturing apparatus and a semiconductor device evaluation apparatus, various adjustments and improvements are made to suppress vibrations.

FIG. 10 is an explanatory view showing an example of a conventional semiconductor manufacturing apparatus. This semiconductor manufacturing apparatus irradiates a wafer 10 as an object to be inspected with an electron beam 3, detects the current (substrate current) generated by the wafer 10 by this irradiation, and the wafer 10 is processed as designed. (See, for example, Patent Documents 1 to 3).

The wafer 10 is placed on the XY stage 7 via the tray 6. The electron beam 3 is emitted from the electron beam source 2. The electron beam 3 passes through the electron boom barrel 4, is converged by a lens 5 disposed at one end of the electron beam barrel 4, and is irradiated so as to be focused on the surface of the wafer 10. And wafer 10, part of electron beam column 4, lens 5. The tray 6, the XY stage 7 and the wafer 10 are accommodated in a vacuum chamber 1 which is controlled in an atmosphere so that an electron beam can be emitted.

[0006] Patent Document 1: Japanese Patent No. 3334750

Patent Document 2: Japanese Patent No. 3292159

Patent Document 3: Japanese Patent No. 3175765

Disclosure of the invention

Problems to be solved by the invention

Further, in order to detect the vibration state of the wafer 10, a configuration in which the vibration sensor 101 is installed on the heel stage 7 can be considered. When the wafer 10 is vibrating, the focal point of the electron beam 3 is also shifted on the surface of the wafer 10, which adversely affects the measurement or processing of the wafer 10. Therefore, a vibration sensor 101 is arranged to confirm that the wafer 10 is not vibrating. Examples of the vibration sensor 101 include an acceleration sensor that converts vibration into an electrical signal, and a laser vibration measurement device that detects vibration by irradiating the surface of a vibrating body with laser and measuring its reflection intensity. The output of the vibration sensor 101 is amplified by the signal amplification device 102 and then analyzed by the waveform analysis device 103 to extract the vibration component.

[0008] For example, a small acceleration sensor has a size of about lcm and a weight of 1 gram. Vibration measurement is performed by actually attaching the acceleration sensor to the vibration measurement location. In the case of a laser vibration measurement device, the size is larger than the 10cm square, so it is placed at a reference location where it is considered that it will not vibrate! In some cases, measurement is performed by using a mirror to convey light to a desired position.

[0009] The conventional vibration sensor 101, such as an acceleration sensor or a laser vibration measuring device, while applying a force, secures a certain place on the inspection object such as the wafer 10, and the acceleration sensor itself or It is necessary to place sensor components (such as mirrors). However, it is very difficult to arrange an acceleration sensor or a mirror directly on the wafer 10. This is because the distance between Ueno 10 and the lens (objective lens) 5 is usually only about 3 mm. Furthermore, even if an acceleration sensor or mirror can be arranged directly on the wafer 10, the acceleration sensor or mirror or the like will adversely affect the measurement and the cache process for the wafer 10 that is the original purpose. [0010] Further, many semiconductor manufacturing apparatuses are placed under harsh conditions such as a vacuum apparatus such as the vacuum chamber 1 or the generation of plasma. Therefore, in conventional semiconductor manufacturing equipment, it is possible in principle to perform measurement by placing an acceleration sensor or mirror experimentally, but it is very difficult to ensure accurate sensor operation over a long period of time. Have difficulty

[0011] In the case of a semiconductor manufacturing apparatus or semiconductor inspection apparatus using an electron beam, maintaining a very high vacuum state is essential for stable operation of the apparatus. However, when an acceleration sensor or a laser vibration measuring device is placed in a vacuum device such as the vacuum chamber 1, the inside of the device may be contaminated.

[0012] The present invention has been made in order to solve the above-described problems of the prior art. Regarding the vibration state of a semiconductor manufacturing apparatus itself or a manufacturing object or an inspection object of a semiconductor manufacturing apparatus, It is an object of the present invention to provide a semiconductor manufacturing apparatus that can detect well without hindering the original manufacturing operation or inspection operation of the semiconductor manufacturing apparatus.

In addition, the present invention provides a semiconductor manufacturing apparatus that can satisfactorily detect the vibration state of a manufacturing object or an inspection object of the semiconductor manufacturing apparatus without providing a vibration sensor separately from the original components of the semiconductor manufacturing apparatus. With the goal.

Means for solving the problem

In order to solve the above problems, a semiconductor manufacturing apparatus according to the present invention processes or measures a semiconductor substrate that is either a semiconductor wafer itself or a semiconductor wafer processed. And it has a capacity | capacitance measurement means which measures the electrical capacitance which arises between the said semiconductor substrate and the peripheral thing arrange | positioned in the vicinity of the semiconductor substrate, or the periphery.

According to the semiconductor manufacturing apparatus of the present invention, the capacitance generated between the semiconductor substrate and the peripheral object can be measured by the capacitance measuring means. For example, the semiconductor substrate becomes the first electrode, the peripheral object (for example, the lens 5 (see FIG. 1)) becomes the second electrode, and the space between the semiconductor substrate and the peripheral object becomes the insulator. A capacitor (capacitance) is formed by the first electrode, the second electrode, and the insulator. When this electric capacity is constant regardless of the passage of time, the distance between the first electrode and the second electrode can be regarded as constant. Therefore, this In this case, it can be considered that the semiconductor substrate is not vibrating. On the other hand, when the electric capacity varies with the passage of time, it can be considered that the interval between the first electrode and the second electrode varies. Therefore, in this case, it can be considered that the semiconductor substrate is vibrating. Since the distance between the first electrode and the second electrode and the electric capacity are inversely proportional, it is possible to detect the magnitude of the vibration by looking at the magnitude of the fluctuation of the electric capacity.

Therefore, the present invention can satisfactorily detect the vibration state of the manufacturing object or inspection object of the semiconductor manufacturing apparatus without providing a vibration sensor separately from the original components of the semiconductor manufacturing apparatus. That is, the vibration state of the manufacturing object or inspection object of the semiconductor manufacturing apparatus can be detected well without hindering the original manufacturing operation or inspection operation.

[0014] Further, the semiconductor manufacturing apparatus of the present invention contains at least the semiconductor substrate and is controlled in an atmosphere so that an electron beam can be emitted, and the electron beam is directed toward the semiconductor substrate. An electron beam source that emits light, and the capacitance measuring unit measures an electric capacitance generated between the semiconductor substrate disposed in the chamber and the peripheral object.

According to the semiconductor manufacturing apparatus of the present invention, it is possible to satisfactorily detect the vibration state of a manufacturing object or an inspection object in a chamber that does not contaminate the atmosphere in the chamber.

[0015] Further, in the semiconductor manufacturing apparatus of the present invention, the capacitance measuring unit sequentially outputs measurement values, and has a waveform analyzing unit that analyzes a change state of the output of the capacitance measuring unit with respect to time. It is characterized by.

According to the semiconductor manufacturing apparatus of the present invention, since the change state of the capacitance with time is analyzed by the waveform analysis means, not only the magnitude of the vibration of the manufacturing object or the inspection object but also where the vibration is located. Can also be detected. For example, it is possible to detect the magnitude of the vibration, the location of the cause of the vibration, etc. by analyzing the change state (waveform) of the capacitance with the passage of time by waveform analysis means by FFT (Fast Fourier Transform) it can.

[0016] Further, the semiconductor manufacturing apparatus of the present invention is based on the output of the waveform analysis means. It has a vibration detecting means for detecting a vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus.

According to the semiconductor manufacturing apparatus of the present invention, for example, based on the waveform obtained by the FFT analysis by the waveform analysis means, the vibration detection means can identify the magnitude of the vibration and the position of the vibration cause.

[0017] Further, in the semiconductor manufacturing apparatus of the present invention, the output of the previous capacity measurement means when the electron beam is irradiated on the semiconductor substrate, and the electron beam is irradiated on the semiconductor substrate. And a vibration detecting means for detecting a vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus based on the output of the previous capacity measuring means.

According to the semiconductor manufacturing apparatus of the present invention, it is possible to detect, for example, whether the cause of vibration is in the electron beam source or the related apparatus or whether there is another cause of vibration.

[0018] Further, in the semiconductor manufacturing apparatus of the present invention, the vibration detection unit is configured to display the vibration state based on the output of the previous capacity measurement unit when the semiconductor substrate is irradiated with the electron beam. When detected, it is determined that there is vibration, and the electron beam is irradiated onto the semiconductor substrate. Based on the output of the previous capacity measuring means, the vibration is detected when the vibration state is detected. If it is determined that there is no electron beam source, it is determined that the electron beam source itself is vibrating.

[0019] In the semiconductor manufacturing apparatus of the present invention, the capacitance measuring unit measures the electric capacity based on a current (substrate current) generated in the semiconductor substrate. The inventors of the present application have found through experiments and the like that this is a function of the magnitude of the capacitance formed by the semiconductor substrate and the peripheral material.

Therefore, according to the semiconductor manufacturing apparatus of the present invention, for example, a separate vibration sensor is not provided in a semiconductor manufacturing apparatus that inspects the processing shape or electrical characteristics of a semiconductor substrate based on the substrate current. The vibration state of a semiconductor substrate or the like can be detected well. In other words, a sensor that detects a processed shape or electrical characteristics of a semiconductor substrate can also be used as a vibration sensor. Here, the processing shape of the semiconductor substrate or electrical The characteristic detection and the vibration detection can be performed simultaneously.

[0020] Further, in the semiconductor manufacturing apparatus of the present invention, the capacitance measuring means generates an electric current generated in the semiconductor substrate when the semiconductor substrate is irradiated with one of an electron beam, an ion beam, light, and an electromagnetic wave (substrate The electric capacity is measured based on a current.

According to the semiconductor manufacturing apparatus of the present invention, the processing shape or electrical characteristics of the semiconductor substrate can be detected using various probes such as an electron beam, ion beam, light, and electromagnetic wave, and the vibration state of the semiconductor substrate or the like can be detected. Can be detected satisfactorily. It is also possible to detect the vibration state of the semiconductor substrate or the like while processing the semiconductor substrate using an electron beam, ion beam, light, electromagnetic wave, or the like.

[0021] Further, in the semiconductor manufacturing apparatus of the present invention, the capacitance measuring means detects secondary electrons generated when the semiconductor substrate is irradiated with an electron beam, and the secondary electron detecting means. And a waveform analysis means for analyzing a change state of the output with respect to time.

The inventor of the present application has found through experiments and the like that the size of the secondary electrons is a function of the size of the electric capacity formed by the semiconductor substrate and the peripheral material.

Therefore, according to the semiconductor manufacturing apparatus of the present invention, for example, a separate vibration sensor is provided in the semiconductor manufacturing apparatus that inspects the processing shape or electrical characteristics of the semiconductor substrate based on the output of the secondary electron detection means. The vibration state of the semiconductor substrate can be detected well. In other words, a sensor that detects a processed shape or electrical characteristics of a semiconductor substrate can also be used as a vibration sensor. Here, the detection of the processing shape or electrical characteristics of the semiconductor substrate and the detection of vibration can be performed simultaneously.

[0022] Further, in the semiconductor manufacturing apparatus of the present invention, the capacitance measuring means detects substrate current detecting means for detecting a current generated in the semiconductor substrate, and secondary electrons generated when the semiconductor substrate is irradiated with an electron beam. A secondary electron detecting means for detecting the substrate current, and a waveform analyzing means for analyzing a change state of the output of the substrate current detecting means and the output of the secondary electron detecting means with time. To do.

According to the semiconductor manufacturing apparatus of the present invention, for example, the substrate current detection means and the secondary electron detector. Based on the output of the output means, it is possible to detect the processing shape or electrical characteristics of the semiconductor substrate with high accuracy, and also detect the vibration state of the semiconductor substrate, etc. without providing a separate vibration sensor with high accuracy. can do.

[0023] Further, the semiconductor manufacturing apparatus of the present invention is characterized in that the waveform analysis means includes difference analysis means for analyzing a difference between an output of the substrate current detection means and an output of the secondary electron detection means. And

According to the semiconductor manufacturing apparatus of the present invention, for example, electrical noise that is commonly included in the output of the substrate current detection means and the output of the secondary electron detection means is removed, and the vibration component is accurately detected. Can be measured.

[0024] Further, the semiconductor manufacturing apparatus of the present invention has irradiation means for irradiating the semiconductor substrate with light or electromagnetic waves used for exposure processing for transferring a desired pattern to the semiconductor substrate, and the capacitance measuring means. Is for measuring the electric capacity based on the current (substrate current) generated in the semiconductor substrate disposed in the vicinity of or around the irradiation means for performing the exposure process. And

According to the semiconductor manufacturing apparatus of the present invention, it is possible to satisfactorily detect the vibration state of the semiconductor substrate exposed in the exposure apparatus through measurement of electric capacitance. Therefore, vibration can be removed in the exposure apparatus, and exposure with higher accuracy is possible.

In the semiconductor manufacturing apparatus of the present invention, the vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is more than a predetermined value by comparing the output value of the waveform analyzing means with a predetermined reference value. Determining means for determining whether or not the vibration state is greater than a predetermined value by the determining means, and management means for displaying at least information indicating a warning on the display means. And

According to the semiconductor manufacturing apparatus of the present invention, for example, when a semiconductor substrate is processed or measured, a warning can be displayed when the semiconductor substrate vibrates to a predetermined value or more. Therefore, it is possible to detect the occurrence of a defective device due to processing or measurement in a large vibration state.

[0026] Further, the semiconductor manufacturing apparatus of the present invention includes an output value of the waveform analysis means and a predetermined reference value. The determination means for determining whether or not the vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is greater than a predetermined value, and the determination means determines that the vibration state is greater than the predetermined value. And a management means for stopping the operation of the semiconductor manufacturing apparatus at least for the processing or measurement. According to the semiconductor manufacturing apparatus of the present invention, for example, processing or measuring a semiconductor substrate is performed. When the semiconductor substrate vibrates to a predetermined value or more, the processing or measurement operation can be stopped. Therefore, it is possible to avoid continuing processing or measuring in a large vibration state.

In the semiconductor manufacturing apparatus of the present invention, the vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is more than a predetermined value by comparing the output value of the waveform analyzing means with a predetermined reference value. And a device related to the semiconductor substrate processed or measured by the semiconductor manufacturing apparatus when the vibration state is determined to be larger than a predetermined value by the determination unit. It has a vibration history creating means for storing at least information to be stored in the storage means.

According to the semiconductor manufacturing apparatus of the present invention, it is possible to identify whether a device is processed or measured in a vibration state larger than a predetermined value (device during vibration). Therefore, for example, it is possible to take measures such as not inspecting the device during vibration, or inspecting it more strictly than other devices. Therefore, the present invention can provide a highly reliable device.

[0028] Further, in the semiconductor manufacturing apparatus of the present invention, the capacitance measuring means includes a stage on which the semiconductor substrate is placed and a case where the semiconductor substrate is placed at a plurality of different positions on the stage. According to the semiconductor manufacturing apparatus of the present invention, the vibration state is detected for each position on the stage. The semiconductor manufacturing apparatus of the present invention includes a position dependency detection unit that detects the vibration state of each position of the stage based on the measured capacitance. Can be detected. Therefore, it is possible to detect a position where the vibration is large or small on the stage, and it is possible to effectively take measures against the vibration. [0029] Further, the semiconductor manufacturing apparatus of the present invention provides a correspondence between the stage on which the semiconductor substrate is mounted and movable, the moving operation of the stage, and the time change of the measurement value of the capacitance measuring means. And a time dependency detecting means for determining whether or not a vibration affecting the machining or measurement has occurred based on the relationship.

According to the semiconductor manufacturing apparatus of the present invention, for example, it is possible to detect that the semiconductor substrate vibrates with the movement of the stage, and the movement of the semiconductor substrate stops after a certain period of time after the movement stops. For example, when the time until the force vibration at the time of movement stop is longer than a certain reference time, it can be determined that the vibration affecting the machining or measurement has occurred. Therefore, according to the present invention, it is easy to take a vibration countermeasure for the stage, and it is easy to provide a highly reliable device.

[0030] Further, the semiconductor manufacturing apparatus of the present invention includes a vibration sensor that detects vibrations of constituent members other than the constituent members that are in direct contact with the semiconductor substrate in the constituent members of the semiconductor manufacturing device, and the capacitance measuring unit. And analyzing means for analyzing the vibration affecting the processing or measurement of the semiconductor substrate and the source of the vibration based on the output of the vibration sensor and the output of the vibration sensor.

According to the semiconductor manufacturing apparatus of the present invention, vibration during processing or measurement of a semiconductor substrate can be analyzed based on the output of the capacitance measuring means and the output of the vibration sensor (acceleration sensor or the like). In view of this, the present invention detects vibration states at different detection positions using sensors having different configurations, so that the vibration state of a manufacturing object or inspection object of a semiconductor manufacturing apparatus can be analyzed with higher accuracy. Become.

The invention's effect

According to the present invention, it is possible to perform vibration measurement without providing a vibration sensor separately from the original components of the semiconductor manufacturing apparatus and without attaching the vibration sensor to the semiconductor substrate. Therefore, the vibration state of the semiconductor manufacturing apparatus and the semiconductor substrate can be detected well without hindering the original manufacturing operation or inspection operation of the semiconductor manufacturing apparatus.

. Therefore, the present invention can improve the defect of the semiconductor manufacturing apparatus using the vibration measurement result (for example, a vibration-proof structure). In addition, according to the present invention, vibration generated in a vacuum can be measured, so that it is not necessary to consider the contamination in the vacuum chamber by the sensor or the destruction of the sensor itself.

In addition, the present invention is not limited to a semiconductor device manufacturing apparatus or evaluation / measurement apparatus using an electron beam or light. The semiconductor device manufacturing apparatus or evaluation 'measuring apparatus uses an electromagnetic wave or ion as a probe (medium). It can also be applied to.

In addition, in any manufacturing equipment such as an etching equipment or CVD (Chemical Vapor Deposition) equipment, the capacity changes according to the vibration generated by the equipment or the electric power that changes in proportion to the vibration. The present invention can be applied to any device that can extract a signal.

[0033] Further, according to the present invention, vibration analysis of a semiconductor manufacturing apparatus can be performed easily and with high accuracy, and a state in which no vibration occurs in the semiconductor manufacturing apparatus can be created by improving the apparatus. become able to. In addition, according to the present invention, a device abnormality caused by vibration can be automatically detected, and an alarm can be displayed and the operation of the device can be stopped in response to the detection. You can also record data about Therefore, it is possible to prevent problems occurring due to abnormal operation of the device due to vibration. In addition, even if a failure occurs, it is possible to easily execute analysis and countermeasures for the failure based on the data remaining in the record.

[0034] Further, according to the present invention, it is possible to perform more complicated vibration analysis by combining the output of the capacitance measuring means and a signal detected by another vibration sensor (acceleration sensor or the like).

Brief Description of Drawings

FIG. 1 is an explanatory view showing a semiconductor manufacturing apparatus according to a first embodiment of the present invention.

FIG. 2 is a waveform diagram showing an example of FFT analysis results for the semiconductor manufacturing apparatus same as above.

FIG. 3 is a waveform diagram showing an example of the result of FFT analysis of a semiconductor manufacturing apparatus after taking measures against vibration.

FIG. 4 is an explanatory view showing a semiconductor manufacturing apparatus according to a second embodiment of the present invention.

FIG. 5 is an explanatory view showing a semiconductor manufacturing apparatus according to a third embodiment of the present invention.

FIG. 6 is an explanatory view showing a semiconductor manufacturing apparatus according to a fourth embodiment of the present invention. FIG. 7 is an explanatory view showing a semiconductor manufacturing apparatus according to a fifth embodiment of the present invention. 8] An explanatory diagram showing a semiconductor manufacturing apparatus according to a sixth embodiment of the present invention. 9] An explanatory view showing a semiconductor manufacturing apparatus according to a seventh embodiment of the present invention. [10] It is an explanatory view showing an example of a conventional semiconductor manufacturing apparatus.

Explanation of symbols

1 ... Vacuum champer

2 ... Electron beam source

2a ... Switch

3 ... electron beam

4 ... Electron beam column

5 ... Lens

6 ... Tray

7 ··· ΧΥ stage

8 ... Board current detector

9… Waveform analyzer

10 ...

11. Waveform recorder

12 ... Secondary electron detector

13 ... Secondary electron detector

14… Waveform analyzer

21 ... Case

22 ... Light source

23 ... light

24 ... Optical system

25 "lens

26 ··· Tray

27 ··· ΧΥ Stage

28 ... Substrate current detector 29… Waveform analyzer

30 ... Management device

31 ··· Display device

41… Vibration sensor

42..Signal amplifier

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the best mode for carrying out the present invention will be described with reference to the drawings.

[0038] (First embodiment)

FIG. 1 is an explanatory view showing a semiconductor manufacturing apparatus according to the first embodiment of the present invention. In the present embodiment, the substrate current generated in the wafer 10 placed inside the semiconductor manufacturing apparatus is measured, and the frequency analysis of the substrate current is performed, so that either the component of the semiconductor manufacturing apparatus or the wafer 10 is analyzed. The present invention relates to an apparatus and a method for finding out whether or not the object vibrates. That is, the semiconductor manufacturing apparatus according to the present embodiment measures vibrations by measuring the electric capacity generated between the wafer 10 and the peripheral object arranged in the vicinity of the wafer 10 through the substrate current. It is.

The semiconductor manufacturing apparatus is an apparatus for measuring or measuring the wafer 10 using the electron beam 3. The wafer 10 is a semiconductor wafer itself such as silicon, for example, and may be a semiconductor substrate obtained by dividing the semiconductor wafer itself.

The semiconductor manufacturing apparatus includes a vacuum chamber 1, an electron beam source 2, an electron beam column 4, a lens (objective lens) 5, a tray 6, an XY stage 7, and a substrate current detection device 8. And a waveform analyzer 9. The vacuum chamber 1 is a container or a room for controlling the atmosphere so that the electron beam 3 can be emitted. In the vacuum chamber 1, a part of the electron beam source 2, an electron beam column 4, a lens 5, a tray 6, an XY stage 7 and a wafer 10 are arranged.

The electron beam source 2 emits an electron beam 3. The electron beam column 4 is a tube through which the electron beam 3 passes, and supports a lens 5 that converges or diffuses the electron beam 3. The lens 5 forms an objective lens that converges the electron beam 3 so that the electron beam 3 is focused on the surface of the wafer 10. Lens 5 consists of a coil, A current is passed through the coil to create a magnetic field and the electron beam is converged by the magnetic field.

. The tray 6 holds the wafer 10. The tray 6 is placed on the XY stage 7. The XY stage 7 is a stage that can be moved precisely in the X and Y directions. By moving the XY stage 7, the electron beam 3 can be irradiated to a desired position of the wafer 10.

The substrate current detection device 8 detects a substrate current that is a current generated in the wafer 10 when the wafer 10 is irradiated with the electron beam 3. The substrate current detection device 8 constitutes a capacitance measuring means for measuring an electric capacitance generated between the wafer 10 and a peripheral object (such as the lens 5) arranged in the vicinity of or around the wafer 10. The waveform analysis device 9 is for sequentially inputting the output of the substrate current detection device 8 and analyzing the waveform. For example, the waveform analyzer 9 performs FFT analysis on the substrate current.

[0043] The substrate current generated in the wafer 10 is a very small current (for example, several pA). Therefore, the vibration of the semiconductor manufacturing apparatus or the wafer 10 during the detection of the substrate current causes a decrease in accuracy of measurement values and a loss of stability.

By the way, whether or not the countermeasure for vibration is perfect in this semiconductor manufacturing apparatus can be known by performing frequency analysis of the substrate current. The wafer 10 that also has silicon power and the semiconductor manufacturing apparatus form an electric capacity. The electric capacity is an electric element generally called a capacitor. A capacitor refers to a structure in which an insulator is sandwiched between two metals (electrodes). A capacitor has the property of storing electric charge. For example, if one of the two electrodes forming the capacitor is formed by the wafer 10, the other electrode is formed by the lens 5, and the space between the wafer 10 and the lens 5 forms an insulator. Conceivable.

[0045] It is known that the amount of charge accumulated in a capacitor increases in inverse proportion to the distance between two electrodes constituting the capacitor. Therefore, if the electrode spacing changes due to vibrations etc., the capacitance of the capacitor changes accordingly. In other words, since this electric capacity fluctuates with vibration, it is possible to know the state of vibration by detecting the change in capacity.

[0046] These electric capacities exist everywhere, such as between the wafer 10 and the lens 5 alone, between the wafer 10 and the tray 6, or between the wafer 10 and the vacuum chamber (housing) 1. ing.

[0047] As a method of knowing the change in the electric capacity, a voltage is applied to the electrode forming the capacity, Examples include a method of measuring the amount of current flowing, or a method of measuring a current generated by a change in capacitance due to a charge previously stored in a capacitive component. There are other methods for knowing the change in capacitance, such as the bridge method, in which no current flows, and any method can be used. The bridge method is to detect changes in the impedance of the sensor by configuring the bridge with four impedances including the sensor and balancing the bridge.

As shown in FIG. 1, the wafer 10 is placed on the tray 6 disposed on the XY stage 7. The wafer 10 and the tray 6 are electrically connected with conductive rubber or the like. The tray 6 force extends the wiring for measuring the substrate current. The wiring is connected to the input terminal of the substrate current detection device 8.

[0049] The substrate current detection device 8 amplifies the input minute current (substrate current) and converts it into a voltage signal that is easy to handle. This voltage signal is recorded as a function of time. For example, a substrate current waveform signal is captured at a sampling period such as 4 OkHz or 4 MHz, converted into a digital signal, and stored. This digital signal is sent to the waveform analyzer 9 for FFT analysis.

FIG. 2 is a waveform diagram showing an example of the result of FFT analysis performed by the waveform analysis apparatus 9 of the semiconductor manufacturing apparatus. In other words, this is an example of the result of FFT analysis of the waveform of the substrate current of the wafer 10. In Fig. 2, the horizontal axis represents frequency, and the vertical axis represents signal intensity (peak intensity). Figure 2 shows an example of analysis of a semiconductor manufacturing device before taking measures against vibration.

[0051] As shown in FIG. 2, the force at which several peaks are detected. Each peak corresponds to vibration of the wafer 10, vibration of the semiconductor manufacturing apparatus, or power supply noise. For example, the peak of 10 OHz is caused by the vibration of the wafer 10, indicating that there is a problem with the method of supporting the wafer 10. The peak at 300 Hz represents the vibration of the semiconductor manufacturing equipment (such as lens 5 or vacuum chamber 1). These have been confirmed experimentally. Such an analysis of the output of the waveform analysis device 9 may be performed manually, but may be performed automatically, for example, when the waveform analysis device 9 also functions as a vibration detection means. That is, the waveform analyzer 9 may detect the vibration state of at least one of the wafer 10 and the semiconductor manufacturing apparatus based on the waveform shown in FIG. 2 output by FFT analysis. Yes.

[0052] Fig. 3 is a waveform diagram showing an example of the result of FFT analysis of the waveform analysis device 9 of the semiconductor manufacturing equipment after taking countermeasures against the vibration cause obtained by the FFT analysis as shown in Fig. 2. is there. In other words, Fig. 3 shows an example of analyzing the substrate current after taking measures against vibration.

FIG. 3 shows that the vibration peak disappears and the cause of the vibration causing the quality deterioration of the manufacturing apparatus and the measuring apparatus has been removed, as is clear when compared with FIG.

[0054] (Second Embodiment)

FIG. 4 is an explanatory view showing a semiconductor manufacturing apparatus according to the second embodiment of the present invention. In FIG. 4, the same components as those of the semiconductor manufacturing apparatus of FIG. The difference between the semiconductor manufacturing apparatus of the present embodiment and the semiconductor manufacturing apparatus of the first embodiment is that the switch 2a and the waveform recording apparatus 11 are provided in the semiconductor manufacturing apparatus.

The switch 2 a is a switch for turning on and off the operation of the electron beam source 2. When switch 2a is ON, electron beam source 2 operates and emits electron beam 3, and when switch 2a is ON, electron beam source 2 stops operating and does not emit electron beam 3. The switch 2a may be constituted by a shirter or the like disposed on the propagation path of the electron beam 3. In this case, the irradiation of the electron beam 3 onto the wafer 10 can be turned on and off while the electron beam source 2 is in an electron beam radiation operation state.

The waveform recording device 11 records the waveform of the substrate current that is the output of the substrate current detection device 8. The waveform recorded by the waveform recorder 11 is analyzed by the waveform analyzer 9 and subjected to vibration analysis.

[0057] The vibration component caused by the semiconductor manufacturing apparatus may vary between when the electron beam 3 is irradiated and when it is not. Therefore, by comparing the data at the time of irradiation with the electron beam 3 and the data at the time of non-irradiation (for example, data stored in the waveform storage device 11), more detailed vibration can be known. For example, noise is observed during electron beam irradiation, and if not, it can be seen that the electron beam source 3 itself is vibrating. The waveform analysis device 9 may have a function as a vibration detection means for detecting such a vibration state or a vibration factor. [0058] (Third embodiment)

FIG. 5 is an explanatory view showing a semiconductor manufacturing apparatus according to the third embodiment of the present invention. In FIG. 5, the same components as those of the semiconductor manufacturing apparatus of FIG. The semiconductor manufacturing apparatus of the present embodiment is an application of the present invention to an apparatus for acquiring a secondary electron image, such as a scanning electron microscope (SEM). The SEM scans the surface of the object to be measured (wafer 10) with the electron beam 3 narrowed down to a few nanometers, and the secondary electrons generated thereby are acquired by the secondary electron detector 12 and the secondary electron detector 13. This is an apparatus that generates an image showing the uneven state of the surface of the measurement target. The waveform analyzer 14 analyzes the vibration state of the wafer 10 or the semiconductor manufacturing apparatus by praying for the change state of the output of the secondary electron detector 13 over time.

[0059] When vibration occurs in an SEM or the like, the image is blurred or distorted, resulting in performance degradation. For example, when the wafer 10 vibrates, the distance from the lens 5 to the wafer 10 changes, so that a focus blur occurs, and the amount of secondary electrons generated in the wafer 10 is modulated. Therefore, eliminating the vibrations of the wafer 10 and the semiconductor manufacturing equipment is very important for maximizing the performance of the equipment.

In the present embodiment, the vibration of the apparatus is measured as follows. First, a wafer 10 having a surface region that has not been subjected to a manufacturing process is set in a semiconductor manufacturing apparatus. That is, the wafer 10 is arranged on the XY stage 7 through the tray 6. Then, the electron beam 3 is scanned on the wafer 10 or a specific place on the wafer 10 is irradiated with the electron beam 3. Secondary electrons generated at this time are detected by a powerful secondary electron detector 12 such as a scintillator and converted into an electrical signal. This electrical signal is stored in a storage device, and further subjected to FFT analysis in the waveform analysis device 14 to obtain a frequency spectrum. These frequency spectrum force vibration sources are identified and semiconductor manufacturing equipment is adjusted and improved.

[0061] (Fourth embodiment)

FIG. 6 is an explanatory view showing a semiconductor manufacturing apparatus according to the fourth embodiment of the present invention. In FIG. 6, the same components as those of the semiconductor manufacturing apparatus in FIG. 1 or 5 are denoted by the same reference numerals. The semiconductor manufacturing apparatus of this embodiment is a combination of the semiconductor manufacturing apparatus of the first embodiment shown in FIG. 1 and the semiconductor manufacturing apparatus of the third embodiment shown in FIG. That is, in this embodiment, vibration analysis is performed using both a signal obtained from the secondary electron detector 12 and a signal obtained from the substrate current detection device 8 (hereinafter simply referred to as “both”). An example is shown. In some cases, both may have a peak at the same frequency. It may not be the case. This semiconductor manufacturing equipment uses these properties to investigate the cause of vibration. When detecting minute vibrations, it may be advantageous to analyze the difference between the two signals to distinguish them from the surrounding electrical noise. Since electrical noise is often included in both, the vibration component can be measured with higher accuracy by using the difference.

[0063] (Fifth embodiment)

FIG. 7 is an explanatory view showing a semiconductor manufacturing apparatus according to the fifth embodiment of the present invention. The semiconductor manufacturing apparatus of the present embodiment is an example in which the present invention is applied to an optical apparatus (for example, a manufacturing apparatus such as an exposure apparatus).

[0064] The semiconductor manufacturing apparatus (exposure apparatus) includes a housing 21, a light source 22, an optical system 24, a lens 25, a tray 26, an XY stage 27, a substrate current detection device 28, and a waveform analysis device. 29. The light source 22 emits light 23 used for exposing the wafer 10. The optical system 24 and the lens 25 converge the light 23 so that the light is focused on the surface of the wafer 10. Therefore, the light source 22, the optical system 24, and the lens 25 constitute an irradiating unit that irradiates the wafer 10 with the light 23 used for the exposure process for transferring the desired pattern onto the wafer 10. The tray 26, the XY stage 27, the substrate current detection device 28, and the waveform analysis device 29 correspond to the tray 6, the XY stage 7, the substrate current detection device 8, and the waveform analysis device 9 of FIG.

The exposure apparatus is an apparatus that requires very high precision positioning. For this purpose, strict temperature control and highly precise XY stage 27 are used. However, the wafer 10 itself, the XY stage 27, or the housing 21 is always exposed to vibrations caused by external forces, which causes deterioration of exposure accuracy.

In addition, since the exposure apparatus is entirely made of metal, an electric capacity is generated between the wafer 10 placed in the exposure apparatus and the exposure apparatus. For example, when the wafer 10 or the exposure apparatus vibrates, a current accompanying a capacitance change is induced in the wafer 10. This current is detected by the substrate current By measuring with the apparatus 28 and analyzing the waveform of the measured value with the waveform analyzing apparatus 29, the cause of vibration of the wafer 10 and the cause of vibration of the exposure apparatus can be known. A high-performance exposure apparatus can be configured by taking anti-vibration measures for the detected cause of vibration.

[0067] (Sixth embodiment)

FIG. 8 is an explanatory view showing a semiconductor manufacturing apparatus according to the sixth embodiment of the present invention. In FIG. 8, the same components as those of the semiconductor manufacturing apparatus of FIG. The semiconductor manufacturing apparatus of this embodiment is an example in which an alarm system is added to the semiconductor manufacturing apparatus of FIG. 7 and the semiconductor manufacturing apparatuses of the other embodiments described above.

[0068] The manufacturing apparatus and the evaluation apparatus may be in a state where desired performance cannot be exhibited when subjected to vibrations exceeding a specified level due to a change in installation environment or the like. If it is unclear whether or not the force is causing vibration during manufacturing or measurement, the wafer 10 processed by the apparatus cannot be properly processed or the measurement value is not correct. Therefore, in the semiconductor manufacturing apparatus of the present embodiment, the apparatus is managed using the vibration signal obtained by the method or configuration shown in each of the above embodiments.

[0069] For example, the substrate current detection device 28 detects vibration data at the time of manufacture or measurement in real time. The waveform analysis device 29 performs vibration analysis such as FFT analysis on the vibration waveform detected by the substrate current detection device 28 in real time, and extracts a vibration peak generated at a certain frequency. The management device 30 compares the management value (reference value) determined for each frequency with the vibration intensity obtained in the actual measurement. Then, the management device 30 displays a warning on the display device 31 when the peak exceeds the management value.

In addition, the management device 30 may have a function of stopping the manufacturing operation or the measurement operation of the semiconductor manufacturing apparatus when the peak exceeds the management value. In addition, when the peak exceeds the control value, the management apparatus 30 does not stop the manufacturing operation or measurement operation of the semiconductor manufacturing apparatus, and indicates that the device is manufactured or measured when there is a lot of vibration. May be transmitted to the host computer and stored as management information. FIG. 8 shows an example of a semiconductor manufacturing apparatus using an optical system. However, an apparatus using an electron beam such as an electron microscope, or a semiconductor such as an etching apparatus or a CVD apparatus is processed. A system similar to that of the present embodiment can be configured by any device such as a device to be used.

[0071] The magnitude of the vibration may be a function of the position on the XY stage 27. For example, when the wafer 10 is brought to a certain position on the XY stage 27, a large vibration is observed, and when the wafer 10 is brought to another certain position, the vibration becomes small. This semiconductor manufacturing apparatus can also specify the vibration source by measuring the position dependency of the vibration signal observed in this way. For example, the waveform analysis device 29 or the management device 30 has a function as a position dependency detection means, and specifies a vibration source in the XY stage 27 or the like.

[0072] In addition, the magnitude of the vibration may have a time dependency with respect to a certain movement of the XY stage 27. For example, it is detected that the wafer 27 vibrates with the movement of the XY stage 27 and that the movement stops and the vibration of the wafer 27 stops after a certain amount of time. And, for example, when the time until the force vibration at the time of movement stop is longer than a certain reference time, it can be determined that the vibration affecting the machining or measurement has occurred. For such a phenomenon, the vibration source can be identified by measuring the time dependence of the FFT analysis waveform in the waveform analyzer 29. The management device 30 sets a management value in advance for the position dependency or time dependency as described above, and if the detected value for the position dependency or time dependency exceeds the control value, the device malfunctions. Can be displayed, and the operation of the equipment can be automatically stopped.

[0073] (Seventh embodiment)

FIG. 9 is an explanatory view showing a semiconductor manufacturing apparatus according to the seventh embodiment of the present invention. In FIG. 9, the same components as those of the semiconductor manufacturing apparatus of FIG. The semiconductor manufacturing apparatus of the present embodiment combines the vibration sensor 41 and the signal amplifying apparatus 42 with the semiconductor manufacturing apparatus of FIG. 1, and performs waveform analysis on the waveform of the substrate current and the output waveform of the vibration sensor 41.

As the vibration sensor 41, for example, an acceleration sensor can be applied, and it is directly attached to the outside of the vacuum chamber 1. The signal amplifying device 42 amplifies the output signal of the vibration sensor 41 and outputs it to the waveform analyzing device 9. For example, there is always some vibration outside the semiconductor manufacturing equipment. Has occurred. By comparing the vibration generated outside and the vibration generated inside the apparatus, it becomes easy to specify the vibration source. The vibration sensor 41 can mainly detect vibration generated outside the apparatus, and the substrate current detection apparatus 8 can mainly detect vibration generated inside the apparatus. Therefore, the waveform analyzer 9 can identify the vibration source with higher accuracy by correlating the signal from the vibration sensor 41 with the substrate current and analyzing the waveform of the correlation.

[0075] The power described in the embodiments of the present invention has been described above. The semiconductor manufacturing apparatus of the present invention is not limited to the above-described embodiments, and various modifications are made without departing from the scope of the present invention. Of course you get.

For example, in the above embodiment, a semiconductor manufacturing apparatus using an electron beam or light has been described. However, the present invention is not limited to this, and the present invention is applied to a semiconductor manufacturing apparatus using an ion beam or various electromagnetic waves. It can also be applied.

Industrial applicability

The present invention is useful for a semiconductor manufacturing apparatus used for manufacturing, inspecting, measuring, or evaluating a semiconductor device. For example, the present invention can be applied to a semiconductor manufacturing apparatus that uses a method of irradiating a semiconductor substrate such as a semiconductor wafer with an electron beam, light, electromagnetic wave, or ion beam.

Claims

The scope of the claims

[1] A semiconductor manufacturing apparatus for processing or measuring a semiconductor substrate that is either a semiconductor wafer itself or a semiconductor wafer processed,

A semiconductor manufacturing apparatus comprising a capacity measuring means for measuring an electric capacity generated between the semiconductor substrate and a peripheral object arranged in the vicinity of or around the semiconductor substrate.

[2] a chamber containing at least the semiconductor substrate and controlled in atmosphere so that an electron beam can be emitted;

An electron beam source that emits an electron beam toward the semiconductor substrate, and the capacitance measuring unit measures an electric capacitance generated between the semiconductor substrate disposed in the chamber and the peripheral object. The semiconductor manufacturing apparatus according to claim 1, wherein:

[3] The capacity measuring means sequentially outputs measurement values,

2. The semiconductor manufacturing apparatus according to claim 1, further comprising a waveform analyzing unit that analyzes a change state of the output of the capacitance measuring unit with respect to time.

4. The semiconductor manufacturing apparatus according to claim 3, further comprising vibration detecting means for detecting a vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus based on an output of the waveform analyzing means. .

[5] Based on the output of the previous capacity measurement means when the semiconductor substrate is irradiated with the electron beam and the output of the previous capacity measurement means when the semiconductor substrate is not irradiated with the electron beam. 3. The semiconductor manufacturing apparatus according to claim 2, further comprising vibration detecting means for detecting a vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus.

[6] The vibration detection means determines that there is vibration when the vibration state is detected based on the output of the previous capacity measurement means when the electron beam is applied to the semiconductor substrate, and the semiconductor substrate When the vibration state is detected, it is determined that there is no vibration based on the output of the previous volume measurement means. 6. The apparatus according to claim 5, wherein it is determined that the object is vibrating. The semiconductor manufacturing apparatus described in 1.

7. The semiconductor manufacturing apparatus according to claim 1, wherein the capacitance measuring means measures the capacitance based on a current generated in the semiconductor substrate.

[8] The capacitance measuring unit measures the capacitance based on a current generated in the semiconductor substrate when the semiconductor substrate is irradiated with any one of an electron beam, an ion beam, light, and an electromagnetic wave. The semiconductor manufacturing apparatus according to claim 1, wherein:

[9] The capacitance measuring unit analyzes a secondary electron detecting unit that detects secondary electrons generated when the semiconductor substrate is irradiated with an electron beam, and analyzes a change state of the output of the secondary electron detecting unit with time. The semiconductor manufacturing apparatus according to claim 1, further comprising: a waveform analysis unit that performs the following.

[10] The capacity measuring means includes:

Substrate current detection means for detecting current generated in the semiconductor substrate;

Secondary electron detection means for detecting secondary electrons generated when the semiconductor substrate is irradiated with an electron beam;

2. The semiconductor manufacturing apparatus according to claim 1, further comprising: a waveform analysis unit that analyzes a change state of the output of the substrate current detection unit and the output of the secondary electron detection unit over time.

11. The semiconductor manufacturing apparatus according to claim 10, wherein the waveform analysis means includes difference analysis means for analyzing a difference between an output of the substrate current detection means and an output of the secondary electron detection means. .

[12] having irradiation means for irradiating the semiconductor substrate with light or electromagnetic waves used in an exposure process for transferring a desired pattern to the semiconductor substrate;

2. The capacitance measuring unit is configured to measure the capacitance based on a current generated in the semiconductor substrate disposed in the vicinity of or around the irradiation unit in order to perform the exposure process. The semiconductor manufacturing apparatus described in 1.

[13] Judgment means for judging whether or not the vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is larger than a predetermined value by comparing the output value of the waveform analysis means with a predetermined reference value; 4. The semiconductor according to claim 3, further comprising a management unit that causes the display unit to display information indicating at least a warning when the determination unit determines that the vibration state is greater than a predetermined value. Manufacturing equipment.

[14] A judgment means for judging whether or not a vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is larger than a predetermined value by comparing an output value of the waveform analysis means with a predetermined reference value;

The management means for stopping the operation of the semiconductor manufacturing apparatus for the processing or measurement at least when the judgment means judges that the vibration state is larger than a predetermined value. The semiconductor manufacturing apparatus as described.

[15] A judgment means for judging whether or not the vibration state of at least one of the semiconductor substrate and the semiconductor manufacturing apparatus is larger than a predetermined value by comparing the output value of the waveform analysis means with a predetermined reference value;

When the determination unit determines that the vibration state is larger than a predetermined value, at least storage unit stores information indicating that the device is a device related to the semiconductor substrate processed or measured by the semiconductor manufacturing apparatus. 4. The semiconductor manufacturing apparatus according to claim 3, further comprising vibration history creating means.

[16] a stage on which the semiconductor substrate is placed;

Position dependency detection for detecting the vibration state at each position of the stage based on the capacitance measured by the capacitance measuring means for each of the semiconductor substrates placed at different positions on the stage. The semiconductor manufacturing apparatus according to claim 1, further comprising: means.

[17] a stage on which the semiconductor substrate is mounted and movable;

A time dependency detecting means for determining whether or not a force has generated a vibration affecting the processing or measurement based on a correspondence relationship between the moving operation of the stage and a time change of the measurement value of the capacity measuring means; The semiconductor manufacturing apparatus according to claim 1, comprising:

[18] a vibration sensor for detecting vibration of a component other than the component in direct contact with the semiconductor substrate in the component of the semiconductor manufacturing apparatus;

Based on the output of the capacitance measuring means and the output of the vibration sensor, the semiconductor substrate 2. The semiconductor manufacturing apparatus according to claim 1, further comprising analysis means for analyzing a vibration that affects processing or measurement of the plate and a generation source of the vibration.